engine quits under load.

engine quits under load.
J

jamesweed

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Orlando, FL.
Vehicle(s)
'85 cj-7, 258, T-5, dana 300, stock diffs; 1967 Chevy Nova 2d HT
Hi,

When going up hill from a stop, or over a burm, ditch etc, and especially backing out of my garage in reverse on my uphill driveway, the engine likes to stall out, after doing some wheezing and coughing/sputtering. I can save it by pushing the clutch in, but she just doesnt like to go when theres a little bit of load involved. I have to keep the rpms way up and burn the clutch through to get going.

The engine has all the original carb(carter bbd w/stepper I believe), and California smog gear. There is a loose red/white wire from the coil that I don't know what is for.

Since I bought the jeep Ive changed the plugs/wires/cap. Did a cranking compression check which yielded good AMC 150 psi results across all cylinders. The EGR valve seems to be working as well as PCV valve is ok.
From what
Ive read the carters with all the vacuum stuff and sensors are a PITA, and I understand very little about them. Thanks.
 
Did we ever find out if tach works? maybe red wire is old tach wire, and a new ne has been hooked up...? Doubt it has to do with the carb, which would be an electronic adjuster of soome sort, but not thinking thats the culprit... :confused:

Anyways, i think you had that particular post if i remember right?

So for the stalling out.

Sounds like a carb problem, since you say from start on hill over bump etc, think it's the carb / mixture / idle setting myself... Maybe the float?? I think you need to try messing with the adjustments on the carb, forget your year before I started posting, but not sure the best method of adjusting those carbs anyway...

You could always switch carb to a MC2100 :cool: but then we have to deal with smog / getting the carb too :cool: Which may be doable??? not sure, but think the MC2100 are perfectly able to be CA smog'ed...

Otherwise it runs fine? Or does it seem like it "should" have more getty-up and go? Does it Idle ok with no load? And do this through all operating temps?

Thinking Carb settings... Though like you said, could be vacuum too??? The vac is a PITA...

Get some more opinions first before buying anything new :notworthy:
:chug:
~ JR
 
I would suggest checking your fuel pump pressure.
 
YEah that was me with the other post about the wire. I have a tach hooked up to the green coil wire, and all is well with that. I doubt that has anything to do with the problem though.

The engine Idles fine only after completely warming up. The electric choke doesnt seem to be working, but that should have no role in the bogging down issues.

I forgot to mention that I changed the fuel pump/inline filter already as well. It seems that this problem isnt as bad when the engine gets to normal operating temp, but I think that even when engine is cold it shouldnt be so bad, when the ambient temp is 90 degrees. Im dreading tryin to get this thing going once winter hits.

I bought this jeep in California, but its in Pennslvania now, so the CA smog checks wont be an issue with some upgrades. My plans are for a 4.0 head with TBI, but not just yet. need more $$, So Id like to get it going as is for now. thanks for your comments!
 
Couple more things to mention: The engine runs fine on straight/level roads.

When it is weezing/sputtering from a stop on an incline and I manage to get it through that dead zone and get my forward speed up a little bit, the engine suddenly takes off and shows some good power/throttle response suddenly, like some somebody threw a switch somewhere to make it all good.
 
Mine was the fuel filter, before had one in, one out. The correct one has one in, two out. one to the carb, one to the fuel return line. wix part number 33040
 
mine turned out to be ignition timing, way retarded., I was lucky enough to still have the tuning decal on rad support that mentioned something the haynes manual doesnt: disconnect electrical connector for vacuum module on fire wall while setting timing. MY jeep was new in California, not sure if its the same for all models as this decal specifies CA emissions standards.
 
well mine started acting up again, so I'll look into the timing...
 
This sounds just like my problems as well and mine is a CA with SMOG :dung:! I just got fed up with the problems and am in the middle of installing a Howell EFI, a CRT HEI Distributor and new Magnaflow exhaust (Catalytic Converter and Magnapack) just for good measure.
If you have a Stepper type Carburetor with an ECM on your AMC 258 i6 / 4.2l then you may be surprised how many wires and the length of vacuum lines they had to use to get through SMOG here in CA. I have a nice pile of sensors, relays, vacuum lines, control modules and wires that have been eliminated.

It may as simple as a Vacuum Leak but after seeing my pile of junk I would absolutely consider an HEI Distributor just to eliminate the Ignition issues (and the wires, plugs, control modules, vacuum lines etc.).
I would also consider another Carburetor. CA SMOG Carburetors were problematic then let alone now, I would bet that a bowl with straws would perform better. Don't forget to get a look into the Muffler, mine had the remnants of the Catalytic Converter inside of it and was most likely at least partially plugged.
 
Last edited:
yeah, I really need the TBI kit in mine, with a 4.0 head. Turns out the jeep runs great now after adjusting the timing last night, but now Im hearing noise coming from the engine when accelerating, worried that its pinging now, I set it to 9 before tdc. previously the mark wasnt even aligned with the timing tab. Maybe I need to do something else when I set timing?

I plugged the dist vaccuum line and disconnected a vacuum module like the sticker says. I may have solved one problem by creating another. Bummer.
 
yep, that's why I went the way that I did. Got the Exhaust closer today and should be able to fire it soon (work gets in the way)
 
I don't have any smog :dung: in my jeep, but I fixed the timing and it seems to be running better, we'll see how it runs in the next few days.
 
I checked my timing again and somehow it migrated way advanced from 9 to about 18 btdc. adjusted back to 9, still pings when accelerating. Anybody know if I need to adjust mixture screws with the timing? I thought the screws are just for Idle mixture which it doesnt Idle so bad.
 
jamesweed said:
Anybody know if I need to adjust mixture screws with the timing? I thought the screws are just for Idle mixture which it doesnt Idle so bad.
Click to expand...

I always do... Not sure if "correct" but I do...

There's the 2 mixture screws (on mine anyways :cool:, on carb bottom "plate" ), which matter through the whole process of running. At any RPM.

Then there is the 1 single idle adjustment screw... (side of carb)

I forget what carb you said you had, but would be good to read up on it for sure and ideal method of adjusting.

If it's pinging does that mean not enough fuel? or too much? I forget... I think it means not enough... If so, the two screws should be adjusted equally. (if you have two also) So to be sure they are, I count while tightening, the rotations til closed all the way, Write it down (cause i forgetful) and the same with other.. If they are equal, add an extra 1/2 turn while re opening to each. (again assuming pinging is due to not enough fuel) Then after that re-adjust idel down to acceptable RPM (I go 700-750) and try it around the block a few times.

Repeat as necessary...

I have seen and since used a trick for easy carb tuning of the mixture screws screws. Use a piece of fuel line (rubber hose) if you have some laying around. I will have to check again to remember the size, but basically the ID hole should fit snug over the mixture screw heads. I cut 2 3" pieces and slide them over the screw heads. They should be tight enough now to tighten / loosen the screws. Then I draw a line on it with soap stone / chalk. I leave mine on so I can always turn my mixture screws easily while on the trail... No screwdriver required. :cool:

Again all this is with my V8 and MC2100 2 Barrel carb... I hope it still applies, someone else will chime in... :notworthy:

:chug:
~ JR
 
Hey everyone.. my 79 CJ5 with the AMC 304 is doing the same thing.. runs great on flat roads.. but offroading it sputters and cant climb anything.. i have a new fuel pump (electric) new lines, and the one in one out fuel filter located on the front of my carb. i have the motorcraft 2100 and did a rebuild kit on it... do you think i need the new fuel filter and adjust the timing? It used to be a california jeep and had all emissions on it.. and well here in az you dont need it so i took it all off.. and it ran way better.. had more power.. but still lags. any ideas? I have been workin on this problem for about 2 months and cant seem to solve it..
 
2 ideas:

The mc2100 carbs are pretty good on tilts from what ive read when set up propper... Check setting again and possibly timing...

2nd idea: i dont have a "3 line fuel" filter on my AMC 304 ??? Not sure what theyre function is??? Maybe with the electric fuel pump its needed?
 
JR74CJ5 said:
2 ideas:

The mc2100 carbs are pretty good on tilts from what ive read when set up propper... Check setting again and possibly timing...

2nd idea: i dont have a "3 line fuel" filter on my AMC 304 ??? Not sure what theyre function is??? Maybe with the electric fuel pump its needed?
Click to expand...


yea im not sure i even need the 3 line.. i think its for the mechanical pumps so the fuel wont just sit...

and thanks.. ill try re-adjusting it and check the timing. :chug:
 
when I had a 2 line filter it was clear and there was pressure in the line, but very little gas was in the filter. it just sputtered in. with the 3 line, there's actually fuel pressure instead of sputtering in
 
gumbycj5 said:
Hey everyone.. my 79 CJ5 with the AMC 304 is doing the same thing.. runs great on flat roads.. but offroading it sputters and cant climb anything.. i have a new fuel pump (electric) new lines, and the one in one out fuel filter located on the front of my carb. i have the motorcraft 2100 and did a rebuild kit on it... do you think i need the new fuel filter and adjust the timing? It used to be a california jeep and had all emissions on it.. and well here in az you dont need it so i took it all off.. and it ran way better.. had more power.. but still lags. any ideas? I have been workin on this problem for about 2 months and cant seem to solve it..
Click to expand...

maybe try checking/adjusting timing. Like I said before, I got rid of the sputtering problem when I set to 9 btdc. But now Ive got pinging. Since I have all the CA smog :dung: still on with the carter bbd, stepper, etc my pinging issue is most likely something in that stuff. Sometimes people in CA tweek timing, mixture to get it to pass the smog checks, while sacrificing performance, then when the vehicle ;leaves CA youve gotta try to find and undo those adjustments.
 
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